The present invention relates to calcium salts of unsaturated fatty acids that are of particular interest as nutritional supplements.
Unsaturated fatty acids undergo hydrogenation to saturated fatty acids by microbial action in the rumen and must be fed to ruminants in a protected form. U.S. Pat. No. 5,143,737 discloses the encapsulation of unsaturated fatty acids with non-toxic organic materials to protect the unsaturated fatty acids from microbial action in the rumen. The most familiar form in which fatty acids in general are protected from microbial action in the rumen are the fatty acid calcium salts disclosed by U.S. Pat. Nos. 4,642,317; 4,826,694; 4,853,233 and 4,909,138. This form of fatty acid protection is widely accepted in the dairy and beef cattle industries.
Unsaturated fatty acids, however, do not readily react to form calcium salts using the processes disclosed by the above-listed patents. Instead of forming free-flowing granules, a mass develops that hardens into a tough material that resists grinding into the fine particles required for consumption by cattle. The resulting material also lacks storage stability. The product tends to auto-oxidize through an exothermic reaction that leads to a congealing of the product mass horn its free flowing granular state to a hard amorphous state, suggesting that significant quantities of unreacted starting materials are present in the final product.
To be commercially viable, rumen-protected unsaturated fatty acid cattle feed supplements must be in a form acceptable to the cattle industry. Therefore, a need exists for unsaturated fatty acid calcium salts that are storage stable and easily formed into particles small enough for cattle to consume that also confer a nutritional benefit to the cattle.